燃烧室形状对柴油机燃烧和排放影响的数值研究

Computational Study of Effect on Combustion Process and Emissions of Diesel Engine by Changing Combustion Chamber Geometry

对相同压缩比的3种燃烧室进行了三维数值计算,分析了燃烧室形状对柴油机燃烧过程、NOx和soot在缸内的分布区域形成的原因,进一步用Φ-T图研究了3种燃烧室在不同时刻对NOx和soot的影响。结果显示:敞口燃烧室更有利于混合气的形成和燃烧,NOx和soot排放低于直口和缩口燃烧室。

Three types of combustion chamber with the same compress ratios was simulated,effect of combustion chamber shape was analyzed on combustion process,origin for the formation of NOx and soot distribution regions in cylinder,the Φ-T diagram was used to investigate impact of three types of combustion chamber on formation region of NOx and soot at different moment.The studies indicated： open combustion chamber is more conducive to the formation of mixture and combustion,on emissions performance,open combustion chamber better than straight combustion chamber and reentrant combustion chamber.